Fluororesin material is widely used for fluid devices in which corrosive fluid, pure water, or the like used for semiconductor production is circulated, because the fluororesin material is superior in chemical resistance and stain resistance.
The fluororesin material has a volume resistivity of more than 1018 Ω·cm and is generally classified as an insulating material. Accordingly, charging due to a friction between a fluid flow channel formed in a fluid device and a fluid may occur in the fluid device formed using the fluororesin material.
To prevent the occurrence of charging, it is possible to impart conductivity to the fluororesin material by containing a conductive material, such as carbon black or iron powder, in the fluororesin material. However, metal ions are eluted from the conductive material due to contact between the conductive material and a fluid, which may result in contamination of the fluid.
In this regard, an antistatic fluororesin tube is known in which a conductive portion made of a fluororesin composition containing a conductive material is embedded in an outer peripheral surface of the antistatic fluororesin tube in a stripe shape to thereby impart conductivity (for example, see Japanese Unexamined Patent Application, Publication No. 2003-4176, hereinafter referred to as “JP 2003-4176”). In the antistatic fluororesin tube disclosed in JP 2003-4176, since the conductive material and the fluid are not in contact, the fluid is not contaminated with metal ions eluted from the conductive material.
A fluid device that adjusts the flow rate of a fluid circulated through a fluid flow channel by adjusting the amount of insertion of a valve body portion to be inserted into a valve bore is known. Further, a fluid device having a structure in which a thin film-like diaphragm portion that isolates a fluid flow channel from an adjacent space adjacent to the fluid flow channel is coupled to the valve body portion is known.